So I solved my "scoring XML" problem from a previous post using XSL stored in Oracle. A simple XMLTransform function later and all of my profiles now get a numeric value. Awesome.
I thought I'd push my luck. I want to put in a hint system so, for instance, if the user has not filled out the work experience section, he might get a message saying "You can get 10 more points by telling us about jobs you've had." I could hardwire the heck out of it, but that's no fun. What I'd like to do is write out a bunch of "hint" elements to the result of the transform, one or more for each section that's not filled out, and then let the interface pick a random one to use. So if my result said something like:
<Hint>Tell us about some jobs</Hint>
<Hint>Take up a hobby</Hint>
<Hint>Get some friends to sign up</Hint>
then I'm looking for a way, using Oracle's XML/XSL functions, to return one of those Hint elements.
It's apparently much harder than it looks. :( The closest I found was something that said I could use "//Hints/Hint[random()]", but Oracle barfs on that syntax. Doesn't like 'random'.
Everything I googled on the subject comes back with stuff about how to generate random sequences. I need to select a random value. One option is to emit each Hint element with some sort of random identifier, and then when it comes time to pick one, just pick a constant. But that's a pain in the neck as well, since I need to be guaranteed I'll get one and only one result, I would have to make sure (without knowing how many Hints I'm to have) that I have adequately spanned the 1-n space just right with my random numbers.
For right now we're leaving the hints off. But it bothers me that something that seems simple -- "Get me one of my random children", does not have an obvious solution.